The DuraHeart, a new experimental, hi-tech heart-assist device, was implanted in Anthony Shannon July 30—a procedure which made history. A week later, the 62-year old Shannon was reported doing well after the operation performed by a team led by surgeon Francis Pagani, M.D., Ph.D. at the University of Michigan Cardiovascular Center. Shannon is the former director of homeland security and emergency management for Wayne County, Mich., and holds a Ph.D, in public administration.
The “maglev” or magnetic levitation technology used means that that a crucial, constantly revolving part within the hockey puck-sized implanted device never touches the walls of the pumping chamber. Instead, it levitates in the middle, suspended in a magnetic field and pushing blood along. The battery-powered device pushes blood from the heart to the body, taking over most of the function of the left side of a severely weakened heart. The advantage of this technology is that the risk of allowing blood clots to form is reduced, as is damage to blood cells, compared with devices using mechanical pumps. DuraHeart has been used for 70 European patients, and received commercial use approval after a 20-07 clinical trial.
A clinical trial for DuraHeart is being conducted by Drs. Pagani and Yoshifumi Naka, M.D.,Ph.D., from Columbia Presbyterian Hospital in New York, and heart failure patients at U-M and other U.S. centers will be invited to volunteer for it.
“The DuraHeart gives us a new, third-generation option for patients with advanced heart failure who need help to allow them to survive until they can receive a heart transplant,” says Pagani, who leads the U-M Center for Circulatory Support. He has led other national clinical trials of heart-assist devices, including the HeartMate II, which in April received approval from the U.S. Food and Drug Administration after a clinical trial. U-M now offers heart failure patients nearly a dozen different options to support their heart function, including heart transplants. U-M is the national training center for the trial, which is funded by Terumo Heart, and teams from Columbia and the University of Louisville have already traveled to Ann Arbor to learn how to implant the device.
“This trial will test the DuraHeart’s potential to overcome some of the issues that have been seen with other devices, including hemolysis caused by shear stress on red blood cells, and clotting risk caused by blood that does not circulate rapidly enough from all areas of the chamber,” Pagani explains. “It also remains to be seen if this device offers superior durability, which might make it useful as a destination therapy that could remove the need for a heart transplant.”
Some 5.3 Americans currently experience heart failure, and at any given time some 4,000 are on a waiting list for heart transplants. Because there is a shortage of suitable organ donors however, only 2,100 people in the U.S. receive new hearts, and hundreds of people die each year while waiting for a new heart. Most of the devices developed to help the heart pump over the past 20 years have been left-ventricular assist systems, known as LVADs or LVASs; others have assisted the right side or both, and all are known as VADs. Hospitals can apply for accreditation as a certified VAD center, and U-M recently became one ofmthe few such centers in the U.S.
The DuraHeart was invented and developed by a team led by Chisato Nojiri, M.D., Ph.D., the chief executive officer of Terumo Heart. More than a decade of research and development has led to this clinical trial and the trial in Europe, as well as a trial in Japan that may begin later this year. Pagani serves as an unpaid consultant to Terumo Heart.
To implant a DuraHeart device, the surgeon diverts blood flow from the ailing left ventricle of the heart into a titanium tube that leads into the pumping chamber. The magnetically levitating impeller, a flat magnetic disc, acts as a paddlewheel, turning constantly as it is magnetically attracted to the turning motor within the pump housing. This pushes blood into a flexible artificial blood vessel, which is connected to the large blood vessel called the ascending aorta.
By assisting the weak left ventricle, which is the heart chamber most commonly affected by heart failure, the DuraHeart allows the heart muscle to rest. It also provides better blood flow to the body, brain and organs than a weak heart ever could – which helps patients prepare for the arduous surgery of a heart transplant.
The DuraHeart is made by Terumo Heart, Inc. based in Ann Arbor, Michigan.
Source: University of Michigan, August, 2008